If you are not receiving any notifications by SMS, then it is likely because you have typed your phone number wrong or chosen the wrong country code during account creation.
To change your phone number:
- Click on [Settings] in the menu
- Click on the pencil icon next to your phone number
- Change your mobile number/country code in the pop-up box
- Click on [Save]
If you are not receiving any notifications by email, start by checking your Spam-folder (and Updates-folder if your use Gmail).
Next, try searching and see if you find the notifications.
If still no luck, please contact support.